A Kent MP has suggested frontline staff in hospitals and carers should be eligible for a fourth jab amid concerns about the level of protection offered by the booster.

Tunbridge Wells MP Greg Clark, who chairs the cross-party select committee on science and technology, said that given research on the efficacy of the third jab there was a case for a fourth.

Speaking in yesterday's debate in the Commons, Mr Clark asked the Prime Minister to keep the option open.

He cited a report published on New Year’s Eve that said the booster waned in its protection against infection but not against serious disease after 10 weeks.

“Given that nurses and care workers had their booster doses last September, 16 weeks ago, is it now right to consider giving these vital workers a fourth dose as is happening for similar workers in Israel?” he asked.

The Prime Minister replied that the government was keeping a close interest in the option.

“I know the JVCI (joint committee on vaccination and immunisation) is keeping this under continuous review,” he said.

There is a question mark over the merits of a fourth dose. Preliminary results of a trial,carried out before Israel embarked on a second booster scheme, showed an extra jab led to a five-fold increase in antibody levels.

That is below the antibody boost of the third vaccine jab.

In a separate development, MPs have called for the government to draw up a plan to tackle the escalating backlog of routine appointments and treatments put on hold because of the pandemic.

Nearly six million people in England are waiting for routine operations and procedures.

A report from MPs on the health select committee says the government needs to address staff shortages - or NHS workers will quit.

The government has confirmed that there are to be no changes to ‘Plan B’ in terms of existing arrangements and restrictions.